Flash grazing is the practice of briefly grazing a pasture with a high concentration of livestock to capitalize on an atypical forage resource.
The combination of drought and grazing stresses often results in abnormally high populations of annuals when the drought breaks, or when good rains occur intermittently during prolonged drought. These species may include palatable annuals like cheatgrass, kochia, lambsquarter, russian thistle or annual sunflower.
Flash grazing stocking rates must be commensurate with the amount of consumable current-year forage. Flash grazing can be a wonderfully cost-effective way to control weeds that are palatable.
Efficient use of annual weeds may require use of a single wire electric fence to concentrate livestock on infested areas.
Annual plants grow and produce seed rapidly. Once heading or flowering begins, palatability drops dramatically. Consequently, relatively high livestock concentrations are often needed to fully use these forage resources before maturity. Flash grazed pastures should not be grazed again in the same year until late summer or after killing frost.